Process of and apparatus for molding plastics.



. APPLICATION FILED OUT. 25, 1909.

Patented June 6,1911

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' Patented Juine 6,1911.

APPLIOATION FILED OUT. 25, 1909.

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' UNITED STATES PATENT OFFICE.

JOHN J. BERRIG-AN, OIE bBANG-E, NEW JERSEY.

rnocn'ss or AND APPARATUS ron MOLDING r'LAsrIos.

- Specification of Letters Patent. PatentedJune 6, 1911.

Application filed October 25, 1909. Serial No, 524,458.

To all whom it may concern: 7

Be it known that I, JonN J. BERRIGAN, a

citizen of the United States, residing at Orange, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Processes of and Apparatus for Molding Plastics, of which the following is a specification.

This invention relates to processes of and apparatus for molding plastics; and it comprises a method of molding concrete and other settable plastics wherein the plastic material is centrifugally positioned and is subjected to centrifugal action during a molding operation; and it also comprises organizations of apparatus elements adapted for use in connection with'such method, said organizations including means for securing a hollow body adapted for rotation about an included axis and adapted to receive and shape a plastic material, means for gradually supplying plastic material to the interior of said hollow body during rotation andmeans forproducing a rapid rotation of said holding means and of said hollowbody secured thereby; all as more fully hereinafter set forth and as claimed.

I11 the manufacture of set concrete articles a number of difliculties are met in producing comparatively thin molded layers of hard, dense, compact and impervious concrete.

7 Portland cement and the like calcareous cemticles of the aggregate.

aggregate such as sand, gravel, rock chips, etc., and the mixture allowed to set. In hydrating, the cement is converted into a solid body permeating the mass and acting, as a matrix or binder for the aggregate, llnking the grains or pieces into a firm and permanent union. The relative amountof cement is preferably soadjusted that it just suffices to fill the voids between the pieces and par- It will be obvious that in making compact and dense concrete tively large amount of a granular filler or it is desirable to use as little water as will suflice for the chemical change of the cement since the addition of more does no good and results in subsequent porosity. With an excess of water, in the ordinary methods of operating, more or less of it will remain as such separated bodies of liquid in the finished concrete, whence it evaporates in But with 1 time, leaving the mass porous. only the, amount of water requisite for the setting of the cement, the concrete mixture is not much more than merely moist and is as stiff and hard to handle as so much moist sand. In order to secure an intimate and uniform commingling of sand, water and ccment, a long and laborious incorporation or working together of the mass is therefore necessary. Such an intimate and uniform commingling is of course a prerequisite for procuring dense and sound concrete; and for this purpose it is furthermore necessary that the working together shall as far as possible obliterate all voids and secure actual contact between the aggregate and the cement matrix at all points. And with a merely moist mixture the amount of labor required to attain this uniformity of composition and homogeneity of texture by working is extreme. And in shaping the resultant concrete, it must be tamped or compressed into the molds with the exertion of much force to secure dense, compact, full strength concrete. The employment of larger amounts of water facilitates the working and incorporation of the ingredients and also the subsequent molding operations to a degree proportional to the amount in excess, since the water renders the mixture fluent and easily worked. In the presence of water theparticles of sand and cement are free to slide over each other. But this ease of working in the usual methods is atthe-expense of the quality of the concrete, that made with an excess of water being usually porous and of relatively low strength. In the present invention, the advantages of both methods of operation are combined and certain new advantages are attained by the mode of operation adopted. A mix- 5 ture is made of the cement and the desired amount of aggregate in the presence of sufiicient water to make the composition freely fluent. -This is more water than is required for thezsetting of the cement, but the excess here does no'harm being later removed, and is even beneficial, as W111 later:

appear. Large excesses may be used "if desired. With this fluent mixture, incorporation and working are easy and little labor is required to produce a thorough and uniform intermingllng of aggregate and binder. The water acts as a lubricant permitting a free relative movement of the particles of aggregate and matrix. The mixture is next exposed in the form of relatively thin layers to a high degree of centrifugal force when the matrix and aggregate separate readily and positively from the excess of water, the concrete components being much heavier than the water and hence compacting against the interior Wall of the apparatus employed in the form of a dense layer, free both of voids and of excess of water, while the water accumulates as an annular layer on the rear of the layer of concrete. Conceiving the layer of-concrete mixture as made up of uniformly incorporated cement and sand, with the finer hydrating cement particles distributed over the faces of the sand grains, with drops or bodies of Water between and separating the sand grains, it will be obvious that when the compound mass is subjected to a compacting centrifugalqaressure the sand grains are free to move toward each other as if in a liquid bath so long as any spaces exist in which they can move. The water. fills all the voids in the mixture as long as the voids exist, but as they disappear, the displaced water moves backward to join the water annulus. The difference between the specific gravity of sand and concrete and that of water is relatively large and, under proper conditions of operation, the separation of the excess of water is absolute, the layer of concrete retaining no more moisture than is required for the setting and becoming, therefore, completely cgmpact and impervious. As stated, as long as any void exists it will be full of water and proxiinto.

mate particles will'be free to move there- This freedom of movement however exists only while the concrete is in relatively thin layers with the backin annulus of water. With a thicker layer time heavy centrifugal pressure acting on the rear of the layer may cause the rearward portions of the mass to press so solidly on the frontward portions as to revent or impede relative movement. An since the great pressure acting on the material is purely radial, there is no tendency of the material to move laterally as a result. An annulus will form, but there is no tendency for the material to move longitudinally, that is, laterally as regards the annulus. In the embodiment of my invention as present preferred, the concrete material is therefore fed into the mold in relatively smallsuccessive. portions and the annulus of "compact concrete so formed is extended laterally longitudinally of the forward by the action of a conveyer.

so that the mass of concrete under pressure is not at any time very thick, the utility of the rear annulus of water back of the concrete annulus is enhanced and there is little danger of particles of the aggregate bridging other particles so as to permit the formation of permanent .voids. This danger is further obviated by the lateral extension which produces a relative movement of the particles of concrete and aid materially in the compacting. Such lateral-movement is of course through the annulus or wall of water. In a cylindrical rotating drum, the water will extend laterally along the length of the drum to form an annulus of the full length of such drum while the concrete will not so extend without mechanical aid. In this method of operation where the concrete mixture is added in successive portions there is the additional advantage that no opportunity is afforded for segregation of the heavier and less heavy portions of the aggregate as distinct layers. Cement and aggregate are deposited in the apparatus in 'a state of substantially uniform admixture and do not again segregate. The centrifugal" pressure employed is preferably rather high. The apparatus may, for instance, rotate at about 500 revolutions per minute. Under these conditions, the concrete is not only exposed to high pressure but is exposed to this pressure in the presence of lubricating water; is compressed while in a rela tively fluent condition. The apparatus employed may be any that is suitable for this form a permanent lining, the article to be lined, such as a pipeor a tank, may be given a rapid rotation about an included axis and the concrete mixture fed therein. Where a molded article is to be formed, the rotating body may be the mold itself, or may be a casing carrying the molds proper.

For lining pipes and tanks, the described process has a number of very important advantages. The lining of concrete may be as thin as may be desired but will still be dense, hard and impervious. is forced against the inner surface of the pipe .or tank under high pressure, it keys positively and effectually into all the superficial irregularities, forming a positive union. Being produced, under outward pressure, after setting the arched layer of concrete retains the stress under which it was formed, and behaves as if the pipe had been shrunk on. A convenient method of operation is to introduce the concrete mixture at one end ofthe pipe and carry it This conveyer may conveniently carry a number of angularly set blades each operating to force the concrete forward toward the other end of the pipe. The mass ofccncrete at the end where it is introduced is carried forward and leveled oil until a uniform annular layer of concrete is formed from end to end' of the tank or pipe. In doing this,

the conveyer bladesalso operate to give the material a glass-like smooth surface, and promote very much the compacting of the layer in the extension laterally of the annulus first formed. At the point where the fluent mixture of concrete materials and water is introdu'ced, the solids and the water tend to Should there be voids in the concrete layer,

form concentric annuli. The water annulus extends throughout the length of the pipe or tank while the concrete annulus is pushed forward through this liquid annulus toward the opposite end of the pipe or tank by the conveyers until it attains the requisite thickness. This layer of concrete being formed in the presence of a layer of water is very easily manipulated and no trouble is experi-fl enced in handling itwith the conveyer.

, these voids become filled with water and the but this aggregate is preferably fine grained.

Either sand or rock powder/may be'employed but advantageously a mixture .of both is used as having a less percentage of voids and requiring less cement than is the case with either sand or rock powder alone.

The ratio between the cement and aggregate may be as desired. .1 part of cement to 3, 4, 5, 6 or 7 parts of aggregate is suitable. Because of its structure the concrete lined pipe or tank so produced may also be regarded as a reinforced concrete article, the exterior metal forming a reinforcing casing.

The described method may also be employed for the manufacture of reinforced concrete pipes, tanks and other vessels containing incorporated metal. By using for the rotating hollow body a separable mold and spacing expanded metal, -wire gauze, netting or other form of reticulated metal therewithin andproceeding as just indicated, a reinforced concrete tube is produced. After the concrete is set the mold can be removed. This will give a dense, compact, very strong reinforced concrete hollow article.

The described method may also be employed for making other than hollow articles as for instance, by providing theinterior of a rotating casing with suitable mold bodies. By placing within the casing a series of cubical molds, concrete bricks may be so made.

In the described method, the working. forward by the conveyers gives the plastic material. a hard, finished, impervious interior surface, the material just below the sweep of the blade not being moved forward by it and the other material traversing the sole so formed. In this molding operation, the lining formed of course takes the contour of the conveying means. In employing concrete mixtures, after forming the main body of the article or lining, a little cement mixture of different composition, as for instance cement with one or two parts very fine sand, or simple neat cement and water, may be fed in to give a hard, polished, glasslikesurface, very impervious and very resist-ant to corrosion. Such a smooth surface is quite desirable in water pipes as lessening friction.

In the accompanyingillustration I hav shown, more or less diagrammatically, certain embodiments of the described invention.

In this showing :-Figure 1 is a vertical longitudinal section of a complete apparatus; Fig. 2 is a transverse section of a mold body for making bricks or tiles; Fig. 3 is a'transverse section of a mold for making. reinforced tubing; Fig. 4 is a transverse section of a lined tube; Fig. 5 is a similar section of a reinforced tube; Fig. 6 is a modified form of the same;.and Fig. 7 is a fragmentary view showing the union between concrete and iron.

In the showing of Fig. 1, element 1 is a suitable base supporting the pedestals 2 and 3, the latter being slidably mounted .as at 4. J ourna-led in the former at5 is a short hollow shaft 6 carrying a pulley wheel 7 and gear Wheel 8. At the other end this shaft is rigid with head 9 and is adapted to impart rotary motion thereto. Within the holshaft at one end carries abeari 21 for the s other end of the described conveyer shaft. WVithin this hollow shaft operates a conveyer 22 driven by wheel 23, receiving material from hopper 24 and feeding the same out through radial outlet 25 in .said hollow shaft. Between the described heads (9 and 20) 110 low'shaft is j ournaled a short stub shaft 10 &

may be secured a cylindrical element 26, this element being either a pipe, or tank to "be lined or amold. Cylinders of various "sizes may be secured between the two heads by bolted lugs 26, and by the adjustability of the end pedestal, similarly, cylinders of various lengths may be accommodated.

Within the cylinder operates a conveyer, shown as a series of angularly set plates 27 mounted on bars 28 which are carried byradial arms 29 from ,the stated conveyer shaft. 30 indicates a layer of concrete within the pipe or mold and 31 a backing annulus of water.

. In theshowing of Fig.2 the cylinder part 26 is made of two halves32 and 33 secured In Fi '3 a mold 42 is shown as provided with, a justable threaded members 43 by which a layer of reinforcing metal may be positioned within the mold at a distance from its walls in making a reinforced tubular body. For convenience in removing the object sogformed from the mold proper, the latter may be made in three parts secured together as at 46. 4 I

In Figs is shown diagrammatically a section of a lined iron ipe, the pipe proper being shown at 47, the layer of plastic at 48 and the described .planished interior layer at 49. 49 may be indicated either by the smoothed surface of the layer itself or a layer of different material, such as a layer of-neat cement.

In Fig. 5 is shown a reinforced concrete pipe or tank, the concrete being indicated by 50, the reinforcement by 51 and .the interior planished layer by 52.

,Fig. 6 shows the concrete body provided with exterior reinforcement 53.

In Fig. 7 is shown diagrammatically on an enlarged and exaggerated scale the bonding or keying between the irregularities 54 of an iron ipe and the concrete layer 55.

The described method and apparatus may I of course be employed for making articles of otherplastics than concrete and for life.

ing articles with such other plastics. For instance, the article may be made of or lined with hot fluent asphalt introduced and handled in the same manner as the concrete mixture. Water glass admixtures can also be used, as maya wide variety of other suitable lastics. In making the concrete other ca careous cements than Portland cement may be used; as for instance plaster of Paris. For Portland cement may be substituted any of theother cements of the same type, such as natural cement, slag cement,

pozzuolana cement, etc. Simplelime mortar may be u sed'for some articles, and the set plastics may be afterward treated with a hardening material, such as alum or water glass.- Portland cement may of course receive admixtures of lime. a

For the sake of simplicity of illustration, the plastic mixture is shown as introduced at only one point, but it may of course be introduced at several, and the resultin plurality of plastic annuli laterally extende till they join to produce the complete annulus of plastic material. In doing this however, the apparatus is necessarily more complicated than the simple types shown; and with concrete thereis moreover a no special advantage in such an introduction at a plurality of points, it being possible in the present invention to employ a thin and fiuentwatery mixture while securing all the advantages ofa thicker, stifi'er mixture as regards the density of the set concrete.

What I claim is 1. The process of molding plastics which comprises gradually feeding a mass of plastic material into the interior and upon the innerwall of a rotating hollow member at one point, said hollow member having a sufficient rate of rotative s eed to centrifugally position said material on its inner wall, and gradually extending the material laterally from said point along said wall.

2. The process of moldin lastics which comprises gradually feedin a fluent mass of material comprising a calcareous cement and water into the interior and upon the inner wall of a, rotating hollow member at one point, said hollow memberhaving a suflicient rate of rotative speed to centrifugally position said material on its inner wall, and gradually extending the material laterally from said point along said wall.

8. The process of molding plastics which comprisesgradually feeding a fluent mass of material comprising a calcareous cement,

water and a filler into the interior and upon the inner wall of a rotating hollow member at one point, said hollow member having a suflicient rate of rotative speed to centrifir.

gally position said material on its inner wall, and radually extending the material laterally ?romsaid point along said Wall. v 4'. The-process of molding plastics which comprises'forming a gradually replenished,-

centrifugally positioned-annulus of plastic material and gradually extending the ma terial of said annulus laterally from the v point of replenishment.

5. The process of molding plastics which comprises formin -a graduall replenished,

centrifugally positioned annuus of plastic of said annulus laterally from thepoint of replenishment.

I 6. The process of molding plastics which comprises forming a gradually replenished, centrifugally positioned annulus of plastic -material in contact with reinforcing metal and gradually extending the material of said annulus laterally along said reinforcing metal from the point of replenishment.

7. The process of molding plastics which comprises forming a gradually replenished, centrifugally positioned annulus of plastic material comprising a calcareous cement and water, in contact with reinforcing metal and gradually extending the material of said annulus laterally along said reinforcingextending the material of said annulus laterally along said reinforcing metal from the point of replenishment. 10. The process of molding plastics which comprises forming a gradually replenished,

centrifugally positioned annulus of plastic material comprising a calcareous cement and water, in contact with and interiorly of a layer of reinforcing metal and gradually extending the material of said annulus later- 40 ally along said reinforcing metal from the point of replenishment.

11. The process of molding plastics which comprises forming a gradually replenished, centrifugally positioned annulus of plastic material comprising a calcareous cement,

water and filler in contact with and interiorly of a layer of reinforcingmetal and gradually extending the materlal of said annulus laterally along said re nforcing metal from the point of replenishment.

12. The process of providing hollow bodies with a lining of plastic material which com-- prises rotating such a body about its axis, forming a gradually replenished, centrlfugally positioned annulus of plastic material at one point on the inner wall of said hollow body and gradually. extending the material of said annulus laterally until said body is provided with the desired thickness of 11n- T3. The process of providinghollow bodies with a lining of plastic material comprlslng a calcareous cement which comprises rotat-v ing such a body about its axis, form ing a gradually replenished, centrifugally positioned annulus of plastic material at one point on the inner wall of said hollow body and gradually extending the material of said annulus laterally until said body is provided with the desired thickness of lining.

14. The process of providinghollow bodies with a lining of plastic material comprising a calcareous cement and filler which comprises rotating such a body about its axis, forming a gradually replenished, centrifu gally positioned annulus of plastic material at one point on the inner wall ofsaid hollow body and gradually extending the material of said annulus laterally until said body is provided with the desired thickness of lin ing.

15. The process of providinghollow bodies with a lining of plastic material which comprises rotating such a body about its axis,

gradually introducing plastic material at one point in its inner periphery and gradually extending said plastic material laterally along said periphery until it forms a complete lining.

16. The process of providinghollow bodies with a concrete lining which comprises rotating such a body about its axis, introducmg a fluent mixture comprising cement and Water at a point on its inner periphery thereby forming a liquid and a solid annulus and gradually extending the solid annulus under the liquid annulus laterally along said periphery from the point of introduction until a complete lining is formed.

17. The process of providing hollow bodies with a concrete lining which comprises rotating such a body about its axis, introducing a fluent mixture comprising cement and water at a point on its inner periphery thereby forming a liquid and a solid annulus, gradually extending the solid annulus under the liquid annulus laterally from such point until a complete lining is formed and frictionally polishing the interior of said lining during the lateral extension of said annulus.

18. The process of molding calcareous i plastics which comprises forming a gradually replenished, centrifugally positioned annulus of cementitious material comprising a filler upon theinterior of a rapidly rotating hollow body, gradually extending said annulus laterally until a uniform layer of the desired thickness is produced, and then introducing cementitious material of different composition and extending the same laterally over the first stated layer. "to form a thin facing layer thereupon.

19. The process of molding-calcareous plastics which comprises forming a gradually replenished, centrifugally positioned annulus of cementitious material comprising a filler upon the interior of "a rapidly-rotat-ing hollow .body, gradually extending said annulus laterally until a uniform layer of the desired thickness is produced, and then introducing cement and water and extending the same laterally over the first stated layer to form a thin facing layer thereupon.- s

20. In a plastic molding apparatus, means for rotating a hollow body about an included axis, means for introducing a plastic mixture at one point on. its inner periphery and means for extending the material of said plastic laterally along said periphery over the interior of said hollow body.

21. In a plastic molding apparatus, means for rotating a hollow body about an included axis, means for introducing a plastic mixture at one point on its inner periphery and conveying means comprising conveyer blades spaced away from said periphery for extending the material of said plastic laterally over the inner periphery.

22. In a plastic molding apparatus, means for rotating a hollow body about an included axis, means for introducing a plastic mixture at one point on its inner periphery and an independently rotatable bladed ccnveyer within said hollow body having blades spaced away from its inner wall;

23. Ina plastic molding apparatus, a pair of rotatable heads adapted to engage the ends of a tubular casing, means for rotating said heads and. easing, means for introducing a plastic material through one of said heads into said casing, and an independently rotatable bladed conveyer having blades reaching toa point somewhat short of the interior of saidcasing located between said said heads, means for introducing plastic material through one of said heads, rotatable conveying means adapted for a journaled engagement with and between said heads and means for giving said conveying means a rotation independent of that of said heads.

25. in a plastic molding apparatus, a pair of rotatable heads adapted to engage and disengage the ends of the tubular casing and impart rotation thereto, means for rotating said heads, means for adjusting one ofsaid heads at variable distances from theother said head, means for introducing plastics through one of said heads, rotatable convey ing means adapted for a journaled engage ment with and between said heads and means for giving said conveying means a rotation independent of that of said head.

26. The process of lining a rotative hollow body provided with revoluble interior conveyer means which comprises placing said hollow body and said conveyer in differential rotary motion, said hollow body being rotated at a suflicient rate of speed to cause centrifugal action therein, feeding plastic concrete material against an interior point of the hollow body and continuing the feed until centrifugal action and the laterally extending action of the conveyer means cooperate to orm a smooth surfaced lining conforming in contour to said conveyer cooperate toform a smooth surfaced-lining I conforming in contour to said conveyer means, a finer grained material being introduced toward the end of the feeding operation to form a finer grained surface, discontinuing the feed and allowing the concrete to harden.

In testimony whereof, I aflix my signature in the presence of witnesses.

. JOHN J; BERRIGAN.

Witnesses:

JoHN S. PAUL, H. E. BENEDICT. 

